Douglas worked originally as an announcer for CBS radio station WCAU in that Philadelphia, relocating to network headquarters in New York in 1934. Douglas co-hosted CBS's popular swing music program, The Saturday Night Swing Club, from 1936 to 1939.

In 1955 he appeared in the play "The Caine Mutiny" but was suspended by his union when he made comments that offended southern audiences about segregation.[4]

Douglas was originally cast in the 1960 episode of The Twilight Zone called "The Mighty Casey", a role written for him by Rod Serling based on his character in Angels in the Outfield. Douglas died the day after production of the episode had been completed. He had been in his last stages of illness during filming, and his severe physical state was apparent on film. (The crew incorrectly assumed that his condition was the result of heavy drinking.) The episode – which was a comedy – was deemed unairable. It was, however, resurrected some months later, and Douglas's scenes were re-shot with Jack Warden.

Paul Douglas died of a heart attack at his home in Hollywood, California on September 11, 1959, at the age of 52.[1] He had just finished filming scenes from a Twilight Zone episode called "The Mighty Casey". As with Angels in the Outfield, he played a manager frustrated by a losing team. Most of his scenes were re-shot with Jack Warden as the manager.

Film director Billy Wilder and his longtime co-writer I. A. L. ('Izzy') Diamond had just offered him the role of Jeff Sheldrake in the 1960 movie The Apartment that went to Fred MacMurray instead. Wilder later said: "I saw him and his wife, Jan Sterling, at a restaurant, and I realized he was perfect, and I asked him right there in the parking lot. About two days before we were to start, he had a heart attack and died. Iz and I were shattered."